Answer:
4.45 m/s
Step-by-step explanation:
Vertical distance, Sy = 5m
The speed of pebble when they hit her window :
Vx = Sx / t
We can obtain t using the relation :
Sy = 1/2 * at²
Where, a = acceleration due to gravity = 9.8m/s²
We can obtain t
5 = 1/2 * 9.8 * t²
5 = 4.9t²
t = √5/4.9
t = 1.01 seconds
Hence,
Speed, Vx = Sx / t
Vx = 4.5 / 1.01
Vx = 4.45 m/s